Advanced glycation end-products increase IL-6 and ICAM-1 expression via RAGE, MAPK and NF-κB pathways in human gingival fibroblasts.

BACKGROUND AND OBJECTIVES: Diabetes mellitus (DM) is a risk factor for periodontal diseases and may exacerbate the progression of the pathogenesis of periodontitis. Advanced glycation end-products (AGEs) cause DM complications relative to levels of glycemic control and larger amounts accumulate in the periodontal tissues of patients with periodontitis and DM. In the present study, we investigated the effects of AGEs on the expression of inflammation-related factors in human gingival fibroblasts (HGFs) to elucidate the impact of AGEs on DM-associated periodontitis. MATERIAL AND METHODS: HGFs were cultured with or without AGEs. Cell viability was examined, and RNA and protein fractions were isolated from AGE-treated cells. The expression of interleukin (IL)-6, intercellular adhesion molecule-1 (ICAM-1), and the receptor for AGE (RAGE) was investigated using reverse transcription-polymerase chain reaction, quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay, and reactive oxygen species activity was measured using a kit with 2',7'-dichlorofluorescin diacetate. Human monocytic cells (THP-1) labeled with a fluorescent reagent were co-cultured with HGFs treated with AGEs and IL-6 siRNA, and the adhesive activity of THP-1 cells to HGFs was assessed. The expression of IL-6 and ICAM-1 was examined when HGFs were pretreated with recombinant human IL-6, the siRNAs of RAGE and IL-6, and inhibitors of MAPK and NF-κB, and then cultured with and without AGEs. The phosphorylation of MAPK and NF-κB was assessed using western blotting. RESULTS: AGEs increased the mRNA and protein expressions of RAGE, IL-6, ICAM-1 and reactive oxygen species activity in HGFs, and promoted the adhesion of THP-1 cells to HGFs, but had no effect on cell viability until 72 hours. Recombinant human IL-6 increased ICAM-1 expression in HGFs, while the siRNAs of RAGE and IL-6 inhibited AGE-induced IL6 and ICAM1 mRNA expression, and IL-6 siRNA depressed AGE-induced THP-1 cell adhesion. AGEs increased the phosphorylation of p38 and ERK MAPKs, p65 NF-κB and IκBα, while inhibitors of p38, ERK MAPKs and NF-κB significantly decreased AGE-induced IL-6 and ICAM-1 expression. CONCLUSION: AGEs increase IL-6 and ICAM-1 expression via the RAGE, MAPK and NF-κB pathways in HGFs and may exacerbate the progression of the pathogenesis of periodontal diseases.

Increased systemic levels of inflammatory mediators following one-stage full-mouth scaling and root planing.

BACKGROUND AND OBJECTIVE: Full-mouth scaling and root planing (FM-SRP) acts as a potent inflammatory stimulus immediately after treatment; however, systemic inflammation typically improves in the long term. The contribution of FM-SRP to systemic biological and acute-phase responses is largely unknown. The purpose of this prospective intervention study was to assess the systemic and local biological responses after FM-SRP. MATERIAL AND METHODS: Thirty-one patients with generalized moderate-to-severe chronic periodontitis received 1-stage FM-SRP. Measurement of clinical parameters and body temperature as well as collection of subgingival plaque, peripheral blood and gingival crevicular fluid was performed before and after treatment 2 or 3 times. Quantification of periodontopathic bacteria in the sulcus and measurement of corresponding serum IgG titers were performed. Systemic and local inflammatory markers such as endotoxin, high-sensitive C-reactive protein (hs-CRP) and 6 inflammatory cytokines were assessed using high-sensitivity assays. RESULTS: Compared to baseline values, FM-SRP resulted in a substantial improvement in clinical parameters (P < .05), lower bacterial counts (P < .01) and a significant decrease of IgG titers against Porphyromonas gingivalis (P < .001) 6 weeks after treatment. Comparing baseline parameters to those at 1 day post-treatment, there was a statistically significant elevation in body temperature (P = .007). In addition, a 5-fold increase in hs-CRP (P < .001), a remarkable increase in interferon-γ (P < .001) and a slight increase in interleukin (IL)-12p70 (P = .001) were detected in serum samples. In the gingival crevicular fluid, marked increases in hs-CRP (P < .001), IL-5 (P = .001), IL-6, IL-12p70 and tumor necrosis factor-α (P < .001 for the latter 3 markers) were noted 1 day after treatment. Endotoxin levels were below measurable limits for most time points. CONCLUSION: FM-SRP resulted in clinical and microbiological improvement 6 weeks post-treatment, but produced a moderate systemic acute-phase response including elevated inflammatory mediators 1 day post-treatment.

Increased serum PCSK9, a potential biomarker to screen for periodontitis, and decreased total bilirubin associated with probing depth in a Japanese community survey.

BACKGROUND AND OBJECTIVES: Previous reports suggest that several serum biomarkers play roles in the pathogenesis, inflammatory response, and oxidative stress in periodontitis caused by bacterial infections, linking chronic periodontitis to atherosclerotic vascular disease (ASVD). The aim of this preliminary study was to investigate, in a Japanese cross-sectional community survey, potential serum biomarkers of periodontitis that are associated with ASVD and chronic periodontitis. MATERIAL AND METHODS: The study cohort included a total of 108 male subjects who underwent annual health examinations. Serum biomarkers (high-sensitivity C-reactive protein [hs-CRP], proprotein convertase subtilisin/kexin type 9 [PCSK9], interleukin-6, tumor necrosis factor-α, soluble CD14, myeloperoxidase, matrix metalloproteinase-3, adiponectin, total bilirubin [TBIL], and serum lipids) were analyzed to determine their association (if any) with periodontal parameters. Aortic stiffness was evaluated using the brachial-ankle aortic pulse wave velocity (PWV) index and the cardio-ankle vascular index (CAVI). RESULTS: The concentrations of PCSK9 and hs-CRP were increased (P = .001 and .042, respectively), and the concentration of TBIL was decreased (P = .046), in subjects with periodontal disease (determined as a probing depth of ≥4 mm in at least one site) compared with periodontally healthy subjects. The ratio of low-density lipoprotein cholesterol (LDL-C) to high-density lipoprotein cholesterol and the concentrations of triglycerides, remnant-like particles-cholesterol, and oxidized LDL were elevated in subjects with periodontal disease compared with periodontally healthy subjects (P = .038, .007, .002, and .049, respectively). Multivariate regression analyses indicated that the number of sites with a pocket depth of ≥4 mm was associated with the concentration of PCSK9 and inversely associated with the concentration of TBIL independently (standardized ß = .243, P = .040; standardized ß = -.443, P = .0002; respectively). Analysis of receiver operating characteristic curves of PCSK9 indicated moderate accuracy for predicting the presence of disease sites (probing depth ≥ 4 mm) (area under the curve = 0.740). No significance in the values of PWV and CAVI was observed between subjects with periodontal disease and periodontally healthy subjects. CONCLUSION: In Japanese male subjects, the concentrations of serum PCSK9 and TBIL were correlated with periodontal parameters. Moreover, PCSK9 could be a candidate biomarker for diagnosing chronic periodontitis, and may also have potential to evaluate the risk for periodontitis to cause ASVD. Longitudinal studies of larger populations are necessary to confirm the exact association of periodontitis with increased serum PCSK9 and decreased TBIL.

Assessing the progression of chronic periodontitis using subgingival pathogen levels: a 24-month prospective multicenter cohort study.

BACKGROUND: The diagnosis of the progression of periodontitis presently depends on the use of clinical symptoms (such as attachment loss) and radiographic imaging. The aim of the multicenter study described here was to evaluate the diagnostic use of the bacterial content of subgingival plaque recovered from the deepest pockets in assessing disease progression in chronic periodontitis patients. METHODS: This study consisted of a 24-month investigation of a total of 163 patients with chronic periodontitis who received trimonthly follow-up care. Subgingival plaque from the deepest pockets was recovered and assessed for bacterial content of Porphyromonas gingivalis, Prevotella intermedia, and Aggregatibacter actinomycetemcomitans using the modified Invader PLUS assay. The corresponding serum IgG titers were measured using ELISA. Changes in clinical parameters were evaluated over the course of 24 months. The sensitivity, specificity, and prediction values were calculated and used to determine cutoff points for prediction of the progression of chronic periodontitis. RESULTS: Of the 124 individuals who completed the 24-month monitoring phase, 62 exhibited progression of periodontitis, whereas 62 demonstrated stable disease. The P. gingivalis counts of subgingival plaque from the deepest pockets was significantly associated with the progression of periodontitis (p < 0.001, positive predictive value = 0.708). CONCLUSIONS: The P. gingivalis counts of subgingival plaque from the deepest pockets may be associated with the progression of periodontitis.

Tumor necrosis factor-alpha gene promoter methylation in Japanese adults with chronic periodontitis and rheumatoid arthritis.

BACKGROUND AND OBJECTIVE: Over-expression of tumor necrosis factor-alpha (TNF-α) plays a pathological role in chronic periodontitis (CP) and rheumatoid arthritis (RA), which might be regulated by the epigenetic mechanism. The aim of the present study was to evaluate whether there is a unique methylation profile of the TNF-α gene promoter in blood cells of individuals with CP and RA. MATERIAL AND METHODS: The study participants consisted of 30 Japanese adults with RA (RA group), 30 race-matched adults with CP only (CP group) and 30 race-matched healthy controls (H group). Genomic DNA isolated from peripheral blood was modified by sodium bisulfite and analyzed, by direct sequencing, to investigate DNA methylation of the TNF-α gene promoter region. The level of TNF-α produced in mononuclear cells stimulated with Porphyromonas gingivalis lipopolysaccharide was determined using ELISA. RESULTS: Twelve cytosine-guanine dinucleotide (CpG) motifs were identified in the TNF-α promoter fragment from -343 to +57 bp. The CP group showed a significantly higher methylation rate and frequency at -72 bp than the H group (p < 0.01). The RA group exhibited significantly higher methylation rates at seven CpG motifs (-302, -163, -119, -72, -49, -38 and +10 bp), and significantly higher methylation frequencies at six CpG motifs (-163, -119, -72, -49, -38 and +10 bp), than the H group (p < 0.01 for all comparisons). The levels of TNF-α produced were significantly different between individuals with and without methylation at -163 bp (p = 0.03). CONCLUSION: These results suggest that the hypermethylated status of CpG motifs in the TNF-α gene promoter in blood cells may be unique to Japanese adults with CP and RA.

Expression of anti-Porphyromonas gingivalis peptidylarginine deiminase immunoglobulin G and peptidylarginine deiminase-4 in patients with rheumatoid arthritis and periodontitis.

BACKGROUND AND OBJECTIVE: Autoimmunity against citrullinated proteins through peptidylarginine deiminase (PAD) may be involved in the pathophysiology of rheumatoid arthritis (RA). The present study evaluated the serum levels of antibodies to citrullinated proteins and to Porphyromonas gingivalis PAD (PPAD), and the endogenous expression of PAD-4, in individuals with and without RA, as well as before and after periodontal treatment. MATERIAL AND METHODS: The study participants consisted of 52 patients with RA (RA group) and 26 age-, gender- and smoking status-matched healthy controls (non-RA group). Of the 52 patients, 26 were randomly assigned to receive oral hygiene instruction and supragingival scaling (RA subgroup). After periodontal and rheumatologic assessments, the serum levels of anti-cyclic citrullinated peptide (CCP) immunoglobulin G (IgG), anti-PPAD IgG and PAD-4 were determined using ELISA. RESULTS: The serum levels of anti-CCP IgG and anti-PPAD IgG were significantly higher in the RA group than in the non-RA group (p < 0.001 and p = 0.03). A significant, positive correlation was observed between the serum levels of anti-PPAD IgG and anti-CCP IgG (p = 0.04), but not between the serum levels of PAD-4 and anti-CCP IgG. Multiple logistic regression analyses revealed a significant association between anti-PPAD IgG responses and RA after adjustment for age, gender and smoking (p = 0.004). Supragingival scaling significantly improved the periodontal condition and disease activity of RA (p < 0.05), but failed to decrease the serum levels of anti-CCP IgG, anti-PPAD IgG and PAD-4 after 2 mo of treatment. CONCLUSION: These results might suggest an association between anti-PPAD IgG and anti-CCP IgG responses, implicating a role for PPAD in protein citrullination in patients with RA and periodontitis.

Salivary pathogen and serum antibody to assess the progression of chronic periodontitis: a 24-mo prospective multicenter cohort study.

BACKGROUND AND OBJECTIVE: A diagnosis of periodontitis progression is presently limited to clinical parameters such as attachment loss and radiographic imaging. The aim of this multicenter study was to monitor disease progression in patients with chronic periodontitis during a 24-mo follow-up program and to evaluate the amount of bacteria in saliva and corresponding IgG titers in serum for determining the diagnostic usefulness of each in indicating disease progression and stability. MATERIAL AND METHODS: A total of 163 patients with chronic periodontitis who received trimonthly follow-up care were observed for 24 mo. The clinical parameters and salivary content of Porphyromonas gingivalis, Prevotella intermedia and Aggregatibacter actinomycetemcomitans were assessed using the modified Invader PLUS assay, and the corresponding serum IgG titers were measured using ELISA. The changes through 24 mo were analyzed using cut-off values calculated for each factor. One-way ANOVA or Fisher's exact test was used to perform between-group comparison for the data collected. Diagnostic values were calculated using Fisher's exact test. RESULTS: Of the 124 individuals who completed the 24-mo monitoring phase, 62 exhibited periodontitis progression, whereas 62 demonstrated stable disease. Seven patients withdrew because of acute periodontal abscess. The ratio of P. gingivalis to total bacteria and the combination of P. gingivalis counts and IgG titers against P. gingivalis were significantly related to the progression of periodontitis. The combination of P. gingivalis ratio and P. gingivalis IgG titers was significantly associated with the progression of periodontitis (p = 0.001, sensitivity = 0.339, specificity = 0.790). CONCLUSIONS: It is suggested that the combination of P. gingivalis ratio in saliva and serum IgG titers against P. gingivalis may be associated with the progression of periodontitis.

Peroxisome proliferator-activated receptor (PPAR) γ polymorphism, vitamin D, bone mineral density and periodontitis in postmenopausal women.

OBJECTIVES: PPARg regulates bone metabolism and inflammation. Our previous study suggested PPARg Pro12Ala polymorphism to represent a susceptibility factor for periodontitis in pregnant Japanese women. Several recent papers have drawn attention to a possible link between low bone mineral density (BMD) and periodontitis in postmenopausal women. Since the pathogenesis for both involve bone remodeling, they might share common risk factors such as gene polymorphisms and vitamin D level. The present study investigated possible associations between the PPARgPro12Ala polymorphism, periodontitis, BMD and serum 25(OH)D in postmenopausal Japanese women. MATERIALS AND METHODS: PPARgPro12Ala genotypes of 359 women were determined by PCR-RFLP. BMD and periodontal parameters of each woman were measured. Serum 25(OH)D levels were determined by radioimmunoassay. RESULTS: PPARgPro12Ala polymorphism was not associated with periodontitis or BMD as an independent factor. Serum 25(OH)D was significantly higher in Ala allele carriers compared to non-carriers. Only in the Ala allele carriers, positive correlations were found between mean clinical attachment level and BMD, between BMD and 25(OH)D, and between percentage of sites with probing depth ≥ 4 mm and 25(OH)D. CONCLUSIONS: PPARgPro12Ala polymorphism was not independently associated with periodontitis or BMD. However, the polymorphism might be a modulator of the relationship between the two conditions in postmenopausal Japanese women.

A Prediction Model for Severe Maternal Morbidity and Mortality After Delivery Hospitalization.

OBJECTIVE: To develop a risk stratification model for severe maternal morbidity (SMM) or mortality after the delivery hospitalization based on information available at the time of hospital discharge. METHODS: This population-based cohort study included all pregnancies among Ohio residents with Medicaid insurance from 2012 to 2017. Pregnant individuals were identified using linked live birth and fetal death records and Medicaid claims data. Inclusion was restricted to those with continuous postpartum Medicaid enrollment and delivery at 20 or more weeks of gestation. The primary outcome of the study was SMM or mortality after the delivery hospitalization and was assessed up to 42 days postpartum and up to 1 year postpartum separately. Variables considered for the model included patient-, obstetric health care professional-, and system-level data available in vital records or Medicaid claims data. Parsimonious models were created with logistic regression and were internally validated. Receiver operating characteristic curves were used to evaluate model performance, and model calibration was assessed. RESULTS: There were 343,842 pregnant individuals who met inclusion criteria with continuous Medicaid enrollment through 42 days postpartum and 287,513 with continuous enrollment through 1 year. After delivery hospitalization discharge, the incidence of SMM or mortality was 140.5 per 10,000 pregnancies through 42 days of delivery and 330.7 per 10,000 pregnancies through 1 year postpartum. The final model predicting SMM or mortality through 42 days postpartum included maternal prepregnancy body mass index, age, gestational age at delivery, mode of delivery, chorioamnionitis, and maternal diagnosis of cardiac disease, preeclampsia or gestational hypertension, or a mental health condition. Similar variables were included in the model predicting SMM or mortality through 365 days with chronic hypertension, pregestational diabetes, and illicit substance use added and chorioamnionitis removed. Both models demonstrated moderate prediction (area under the curve [AUC] 0.77, 95% CI 0.76-0.78 for 42-day model; AUC 0.72, 95% CI 0.71-0.73 for the 1-year model) and good calibration. CONCLUSION: A prediction model for SMM or mortality up to 1 year postpartum was created and internally validated with information available to health care professionals at the time of hospital discharge. The utility of this model for patient counseling and strategies to optimize postpartum care for high-risk individuals will require further evaluation.

Association of the FcγRIIB-nt645+25A/G polymorphism with the expression level of the FcγRIIb receptor, the antibody response to Porphyromonas gingivalis and the severity of periodontitis.

BACKGROUND AND OBJECTIVE: Human FcγRIIb is an immunoglobulin G (IgG) receptor that inhibits the activation of B lymphocytes through cross-linking with the B-cell receptor via immune complexes. This function acts as a negative regulator of antibody production. Our previous studies have demonstrated the gene polymorphisms in FcγRIIb to be associated with periodontitis. In this study, we presented a polymorphism--FcγRIIB-nt645+25A/G (rs2125685)--in intron 4 and analyzed its functional relevance to periodontitis. We examined whether the FcγRIIB-nt645+25A/G polymorphism is associated with periodontal parameters, the IgG response to the periodontopathic bacterium Porphyromonas gingivalis and/or the expression level of FcγRIIb on peripheral B lymphocytes. MATERIAL AND METHODS: Thirty-two patients with chronic periodontitis were genotyped with nested PCR and by direct sequencing of genome DNA. The levels of serum IgG and of specific IgG subclasses for P. gingivalis sonicate and for the recombinant 40-kDa outer membrane protein (OMP) were determined. The expression levels of FcγRIIb on peripheral B lymphocytes from 19 healthy donors were measured by flow cytometry. RESULTS: Patients with the FcγRIIB-nt645+25AA genotype showed significantly higher mean clinical attachment levels compared to patients with the FcγRIIB-nt645+25GG genotype (p = 0.003) and a significantly lower IgG response to P. gingivalis sonicate and to the 40-kDa OMP. The expression levels of FcγRIIb protein on the cell surface in peripheral B lymphocytes were higher in healthy donors with the FcγRIIB-nt645+25AA genotype than in those with the FcγRIIB-nt645+25GG genotype (p = 0.03). CONCLUSION: The higher expression levels of FcγRIIb in subjects with the FcγRIIB-nt645+25AA genotype may induce a lower level of production of IgG against P. gingivalis and therefore more severe periodontitis.

FcγRIIB-nt645+25A/G gene polymorphism and periodontitis in Japanese women with preeclampsia.

FcγRIIB contains a unique immunoreceptor tyrosine-based inhibition motif (ITIM) and functions as a negative feedback regulator of leucocyte activation and antibody production. We have previously reported FcγRIIB-nt645+25A/G gene polymorphism to be associated with prevalence and severity of periodontitis, FcγRIIB expression level on peripheral B lymphocytes and the serum IgG level against periodontopathic bacteria. Previous studies have reported maternal periodontal disease to be associated with an increased risk for preeclampsia. Therefore, FcγRIIB-nt645+25A/G gene polymorphism may be associated with preeclampsia by affecting immune response to periodontopathic bacteria in pregnant women. To elucidate whether FcγRIIB-nt645+25A/G gene polymorphism has associations with preeclampsia and/or periodontitis in pregnant Japanese women, a case-control study was carried out on women with preeclampsia (n = 13) and without preeclampsia (n = 106). Maternal periodontal parameters and bacterial data of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia in subgingival plaque were collected within 5 days of delivery. FcγR genotypes of each woman were determined using the genomic DNA isolated from peripheral blood. Serum IgG levels specific for each bacteria were determined. There was a significant association between FcγRIIB-nt645+25A/G polymorphism and preeclampsia (P = 0.013). The frequency of the FcγRIIB-nt645+25AA genotype was higher in the preeclampsia group compared with the nonpreeclampsia group (P = 0.007). The DNA level of A. actinomycetemcomitans from subgingival plaque was shown to be higher in the preeclampsia group (P = 0.017). In conclusion, maternal FcγRIIB-nt645+25A/G polymorphism and subgingival DNA level of A. actinomycetemcomitans were significantly associated with the prevalence of preeclampsia in a limited number of Japanese women independently with periodontal infection. Further investigations should be performed to confirm this association in a larger population and to determine the biological process of the association.

Association of Prepregnancy Body Mass Index With Risk of Severe Maternal Morbidity and Mortality Among Medicaid Beneficiaries.

Importance: The association between body mass index (BMI, which is calculated as weight in kilograms divided by height in meters squared) and severe maternal morbidity (SMM) and/or mortality is uncertain, judging from the current evidence. Objective: To examine the association between prepregnancy BMI and SMM and/or mortality through 1 year post partum and to identify both the direct and indirect implications of maternal obesity for SMM and/or mortality by examining hypertensive disorders and pregestational diabetes as potential mediators. Design, Setting, and Participants: This population-based cohort study was conducted from March to October 2021 using the vital records and linked Medicaid claims data in the state of Ohio from January 1, 2012, through December 31, 2017. The cohort comprised pregnant Medicaid beneficiaries who delivered at 20 weeks' gestation or later and had prepregnancy BMI information. Exposures: The primary exposure was maternal prepregnancy BMI, which was categorized as follows: underweight (<18.5), healthy weight (18.5-24.9), overweight (25.0-29.9), class 1 obesity (30.0-34.9), class 2 obesity (35.0-39.9), and class 3 obesity (≥40.0). Main Outcomes and Measures: The primary outcome was a composite of SMM (defined using Centers for Disease Control and Prevention criteria) and/or maternal mortality between 20 weeks' gestation and 1 year post partum. Additional periods were assessed, including 20 weeks' gestation through delivery hospitalization and 20 weeks' gestation through 42 days post partum. Generalized estimating equation models were used to estimate adjusted relative risks (aRRs) for the primary outcome according to BMI category. Maternal hypertensive diseases and pregestational diabetes were assessed as potential meditators. Results: In a cohort of 347 497 pregnancies among 276 691 Medicaid beneficiaries (median [IQR] maternal age at delivery, 25 [21-29] years; 210 470 non-Hispanic White individuals [60.6%]), the prevalence of maternal obesity was 30.5% (n = 106 031). Composite SMM and/or mortality outcome occurred in 5.3% of pregnancies (n = 18 398). Overweight (aRR, 1.07; 95% CI, 1.03-1.11) and obesity (class 1: aRR, 1.19 [95% CI, 1.14-1.24]; class 2: aRR, 1.37 [95% CI, 1.30-1.44]; class 3: aRR, 1.71 [95% CI, 1.63-1.80]) were associated with an elevated risk of SMM and/or mortality during pregnancy to 1 year post partum compared with healthy BMI. Similar findings were observed when the follow-up period was shortened to 42 days post partum or the delivery hospitalization. Hypertension mediated 65.1% (95% CI, 64.6%-65.6%) of the association between obesity and the primary outcome. Conclusions and Relevance: Results of this study showed that maternal prepregnancy obesity was associated with an elevated risk of SMM and/or mortality. Hypertensive disorders appeared to mediate this association, suggesting that improved prevention and management of hypertensive disorders in pregnancy may reduce morbidity and mortality in individuals with obesity.

FcγRIIB polymorphisms, periodontitis and preterm birth in Japanese pregnant women.

BACKGROUND AND OBJECTIVE: Recently, numerous studies have investigated the association of preterm birth with periodontitis. FcγRIIb is a human low-affinity receptor for immunoglobulin G (IgG). We have previously demonstrated single nucleotide polymorphisms (SNPs) of FcγRIIb to be associated with periodontitis and the serum-specific IgG level against periodontopathic bacteria. In this study, we investigated whether FcγRIIB gene polymorphisms were associated with periodontitis and/or pregnancy outcome. MATERIAL AND METHODS: We assessed the periodontal conditions of 122 Japanese pregnant women within 5 d of delivery, and polymorphisms in FcγRIIB and in other Fcγ receptors were detected from the genomic DNA. Using clinical and genomic data, we analyzed the relationship between periodontitis, preterm birth and Fcγ receptor polymorphisms. RESULTS: A significant difference was observed in the distribution of FcγRIIB-nt645+25A/G (rs2125685) between preterm and term birth groups, with a higher prevalence of nt645+25AA in the preterm birth group (p = 0.032). Additionally, the FcγRIIB-nt645+25GG carrier showed significantly higher results for the prevalence of periodontitis (p = 0.048), mean pocket depth (p = 0.021), mean clinical attachment level (p = 0.010), percentage of sites with pocket depth ≥ 4 mm (p = 0.005) and percentage of sites with clinical attachment level ≥ 3 mm (p = 0.007) than the AA carrier. An association between preterm birth and periodontitis was not observed in this study. CONCLUSION: These findings suggest that FcγRIIB-nt645+25AA carriers are more likely to experience preterm birth than FcγRIIB-nt645+25AG and GG carriers. Also, women with FcγRIIB-nt645+25G exhibited a greater tendency to have periodontitis than those with nt645+25A.

Altered gene expression in leukocyte transendothelial migration and cell communication pathways in periodontitis-affected gingival tissues.

BACKGROUND AND OBJECTIVE: Gene expression is related to the pathogenesis of periodontitis and plays a crucial role in local tissue destruction and disease susceptibility. The aims of the present study were to identify the expression of specific genes and biological pathways in periodontitis-affected gingival tissue using microarray and quantitative real-time RT-PCR analyses. MATERIAL AND METHODS: Healthy and periodontitis-affected gingival tissues were taken from three patients with severe chronic periodontitis. Total RNAs from six gingival tissue samples were used for microarray analyses. Data-mining analyses, such as comparisons, gene ontology and pathway analyses, were performed and biological pathways with a significant role in periodontitis were identified. In addition, quantitative real-time RT-PCR analysis was performed on samples obtained from 14 patients with chronic periodontitis and from 14 healthy individuals in order to confirm the results of the pathway analysis. RESULTS: Comparison analyses found 15 up-regulated and 13 down-regulated genes (all of which showed a change of more than twofold in expression levels) in periodontitis-affected gingival tissues. Pathway analysis identified 15 up-regulated biological pathways, including leukocyte transendothelial migration, and five down-regulated pathways, including cell communication. Quantitative real-time RT-PCR verified that five genes in the leukocyte transendothelial migration pathway were significantly up-regulated, and four genes in the cell communication pathway were significantly down-regulated, which was consistent with pathway analysis. CONCLUSION: We identified up-regulated genes (ITGB-2, MMP-2, CXCL-12, CXCR-4 and Rac-2) and down-regulated genes (connexin, DSG-1, DSC-1 and nestin) in periodontitis-affected gingival tissues; these genes may be related to the stimulation of leukocyte transendothelial migration and to the the impairment of cell-to-cell communication in periodontitis.

Characterization of human-type monoclonal antibodies against reduced form of hemin binding protein 35 from Porphyromonas gingivalis.

BACKGROUND AND OBJECTIVE: The gram-negative anaerobe Porphyromonas gingivalis has been implicated as an important pathogen in the development of adult periodontitis, and its colonization of subgingival sites is critical in the pathogenic process. We previously identified a 35 kDa surface protein (hemin binding protein 35; HBP35) from P. gingivalis that exhibited coaggregation activity, while additional analysis suggested that this protein possessed an ability to bind heme molecules. For development of passive immunotherapy for periodontal diseases, human-type monoclonal antibodies have been prepared using HBP35 as an antigen in TransChromo mice. In the present study, we focused on a single antibody, TCmAb-h13, which is known to inhibit heme binding to recombinant HBP35. The aim of our investigation was to clarify the redox-related function of HBP35 and consider the benefits of human-type monoclonal antibodies. MATERIAL AND METHODS: To examine the antigen recognition capability of TCmAbs with immunoblotting and Biacore techniques, we used the native form as well as several Cys-to-Ser variants of recombinant HBP35. RESULTS: We found that the redox state of recombinant HBP35 was dependent on two Cys residues, (48) C and (51) C, in the thioredoxin active center (WCGxCx). Furthermore, TCmAb-h13 recognized the reduced forms of recombinant HBP35, indicating its inhibitory effect on P. gingivalis growth. CONCLUSION: Hemin binding protein 35 appears to be an important molecule involved in recognition of the redox state of environmental conditions. In addition, TCmAb-h13 had an inhibitory effect on heme binding to recombinant HBP35, thereby interfering with P. gingivalis growth.

Proteomic profiling of human neutrophils in relation to immunoglobulin G Fc receptor IIIb polymorphism.

BACKGROUND AND OBJECTIVE: Neutrophils are essential in host defense against periodontopathic bacteria. Immunoglobulin G Fc receptor IIIb (FcγRIIIb) is a neutrophil-specific receptor for immunoglobulin G and bears the functional NA1-NA2 polymorphism. Accumulating evidence suggests a significant association between FcγRIIIb gene polymorphism and periodontitis. In this study, we employed a proteomic approach to evaluate the relevance of FcγRIIIb polymorphism to protein expression profiles of neutrophils. MATERIAL AND METHODS: Neutrophils were collected from ten healthy subjects whose FcγRIIIb genotypes were determined by allele-specific PCRs. Expressions of proteins induced by interaction via FcγRIIIb were examined between the FcγRIIIb genotypes with two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis. Proteins that were significantly different in expression levels between the FcγRIIIb genotypes were determined with computer image analysis, and identified with mass spectrometry and protein databases. RESULTS: A total of 757 protein spots were observed in the two-dimensional electrophoretograms of neutrophils from five FcγRIIIb-NA1/NA1 and five FcγRIIIb-NA2/NA2 donors. A statistical analysis revealed that the expression levels of five proteins were significantly different between the FcγRIIIb genotypes (p < 0.05). The FcγRIIIb-NA1/NA1 neutrophils exhibited two spots that were significantly underexpressed (protein-arginine deiminase type-4 and annexin VI) and three spots that were significantly overexpressed (Cdc42hs-Gdp complex, myosin light chain 12A and coactosin-like 1) when compared with FcγRIIIb-NA2/NA2 neutrophils. The same expression profiles of protein-arginine deiminase type-4 were obtained by ELISA. CONCLUSION: Differential protein expression profiles were observed in neutrophils between FcγRIIIb genotypes.

Lower antibody response to Porphyromonas gingivalis associated with immunoglobulin G Fcgamma receptor IIB polymorphism.

BACKGROUND AND OBJECTIVE: Human FcgammaRIIB is one of the receptors for immunoglobulin G (IgG) and suppresses the activation of B lymphocytes through cross-linking with the B cell receptor via immune complexes. This function of FcgammaRIIB is essential for the negative regulation of antibody production. Our previous study has demonstrated the gene polymorphism FcgammaRIIB-I232T to be associated with periodontitis. The polymorphism FcgammaRIIB-232T has been reported to inhibit B-cell antigen receptor signaling more effectively compared to FcgammaRIIB-232I, while other groups concluded that FcgammaRIIB-232T had no ability to inhibit activatory receptors. In this study, we examined whether FcgammaRIIB-I232T polymorphism would change the IgG antibody response to the periodontopathic bacteria Porphyromonas gingivalis. MATERIAL AND METHODS: Forty-seven patients with periodontitis were genotyped with the direct sequencing of genome DNA. Serum IgG and specific IgG subclass levels for the sonicate of P. gingivalis and the recombinant 40 kDa outer membrane protein (OMP) were determined. RESULTS: No significant difference in the total IgG level and IgG response to P. gingivalis sonicate were observed between sera from FcgammaRIIB-232T carriers and non-carriers. The FcgammaRIIB-232T carriers revealed a significantly lower IgG(2) response to P. gingivalis 40 kDa OMP compared to non-carriers (p = 0.04, Mann-Whitney U-test). Lower responses of FcgammaRIIB-232T carriers were also observed in specific IgG and IgG(1) levels. The FcgammaRIIB-232T carriers revealed a low level of IgG(2) response to P. gingivalis 40 kDa OMP, even with a high average probing pocket depth. CONCLUSION: These results suggest that association of the FcgammaRIIB-232T allele with periodontitis might be related to the lower levels of antibody response to P. gingivalis.

Association of interleukin-1 receptor antagonist +2018 gene polymorphism with Japanese chronic periodontitis patients using a novel genotyping method.

Genetic variants at multiple loci have been shown to be associated with periodontitis risk. In this study, we have focused on nine functional gene polymorphisms encoding immunoregulation-related molecules such as cytokines (interleukin-1 (IL-1), transforming growth factor-beta1 (TGF-beta1)) and cell surface receptors (immunoglobulin G and A Fc receptors (Fc gamma R and Fc alpha R)). In total, 113 Japanese patients with chronic periodontitis (CP) and 108 race-matched healthy controls were genotyped with the modified serial invasive signal amplification reaction. There was a significant difference in the distribution of IL-1 receptor antagonist (RN) +2018 T/C allele between the patient and control groups, with enrichment of the +2018 C in controls (P = 0.021, odds ratio = 0.38). An increased frequency of the IL-1 haplotype comprising IL-1A +4845 G, IL-1B -31 C, and IL-1RN +2018 C was observed in controls (P = 0.004). Moreover, a multivariate logistic regression analysis revealed that subjects with IL-1RN +2018 C allele were less likely to have CP (P = 0.016, odds ratio = 0.29). These findings document the association of IL-1RN +2018 C with reduced susceptibility to CP in the Japanese.

Expression of neprilysin in periodontitis-affected gingival tissues.

OBJECTIVE: Although the pathogeneses of Alzheimer's disease (AD) and periodontal diseases have overlapping features, including ageing and chronic inflammation, the association between AD and periodontitis remains unclear. To explore the pathogenesis of periodontitis, a comprehensive gene expression/transcriptome analysis in periodontitis-affected gingival tissues found that the AD pathway was significantly up-regulated in periodontitis-affected gingival tissues. AD-related genes, amyloid beta precursor protein (APP), interleukin-1 beta and compliment 1QA, were significantly elevated in periodontitis. In the present study, balance between mRNA expression of APP and a potent amyloid degradation enzyme, neprilysin (NEP), as well as protein localisation of APP and NEP were analysed. DESIGN: Eighteen periodontitis-affected and 18 clinically healthy control gingival tissues were taken from patients with severe chronic periodontitis or undergoing tooth extraction. Total RNA was purified and used for quantitative reverse transcription real-time polymerase chain reaction (qRT-PCR). The localisation of APP and NEP was analysed by immunohistochemistry (IHC). RESULTS: Both APP and NEP genes were up-regulated in periodontitis-affected gingival tissues. APP-expressing macrophages and NEP-expressing neutrophils and fibroblasts, reflecting inflammatory stages, were detected in inflamed gingival tissues by IHC. CONCLUSION: The up-regulation of APP and NEP mRNA levels in periodontitis-affected gingival tissues compared with healthy controls was confirmed by qRT-PCR analyses. Since NEP is one of the primary enzymes that degrades amyloid beta, increased NEP mRNA levels in periodontitis may act as an inhibitor of amyloid beta accumulation in gingival tissues, balancing increased APP mRNA expression. However, NEP has several effects including degradation of vasoactive substances; therefore, further sresearch is needed.

Orthotopic Kidney Transplantation in an Elderly Patient With Various Severe Comorbid Conditions: A Case Report.

In recent years, the frequency of high-risk kidney transplantations has increased. We report a case in which a 72-year-old man with various severe comorbidities (prostate cancer, diabetes mellitus, complete atrioventricular block, coronary artery stenosis, severe stenosis of the popliteal arteries, and severe calcification of the iliac arteries) who received an orthotopic kidney transplantation. To prevent the occurrence of acute limb ischemia due to the steal phenomenon (caused by the kidney graft), we decided that a heterotopic kidney transplantation involving the iliac arteries was not an appropriate option. Therefore, as an alternative, left native nephrectomy was performed followed by an orthotopic kidney transplantation to the native renal artery and renal vein through a left subcostal incision. Postoperative ureteral stenosis occurred, and so stent exchange was required every 6 months. Despite the ureteral complication, the patient's serum creatinine level was 1.5 mg/dL at 2 years after the procedure.